import assert from 'node:assert/strict';
import fs from 'node:fs/promises';
import path from 'node:path';
import test from 'node:test';
import vm from 'node:vm';

const root = path.resolve(import.meta.dirname, '..');
const GPX_NAMESPACE = 'http://www.topografix.com/GPX/1/1';
const POI_NAMESPACE = 'urn:wegwichtel:poi';

function escapeXml(value) {
  return String(value)
    .replaceAll('&', '&')
    .replaceAll('<', '&lt;')
    .replaceAll('>', '&gt;')
    .replaceAll('"', '&quot;')
    .replaceAll("'", '&apos;');
}

function decodeXml(value) {
  return String(value)
    .replaceAll('&lt;', '<')
    .replaceAll('&gt;', '>')
    .replaceAll('&quot;', '"')
    .replaceAll('&apos;', "'")
    .replaceAll('&amp;', '&');
}

class XmlElement {
  constructor(namespaceURI, tagName) {
    this.namespaceURI = namespaceURI;
    this.tagName = tagName;
    this.localName = tagName.includes(':') ? tagName.split(':').at(-1) : tagName;
    this.attributes = new Map();
    this.children = [];
    this.parentNode = null;
    this._text = '';
  }

  get firstChild() {
    return this.children[0] || null;
  }

  get textContent() {
    return this._text + this.children.map(child => child.textContent).join('');
  }

  set textContent(value) {
    this.children = [];
    this._text = String(value ?? '');
  }

  appendChild(child) {
    child.parentNode = this;
    this.children.push(child);
    return child;
  }

  insertBefore(child, reference) {
    child.parentNode = this;
    const index = reference ? this.children.indexOf(reference) : -1;
    if (index < 0) this.children.push(child);
    else this.children.splice(index, 0, child);
    return child;
  }

  remove() {
    if (!this.parentNode) return;
    this.parentNode.children = this.parentNode.children.filter(child => child !== this);
    this.parentNode = null;
  }

  setAttribute(name, value) {
    this.attributes.set(name, String(value));
  }

  getAttribute(name) {
    return this.attributes.has(name) ? this.attributes.get(name) : null;
  }

  getElementsByTagName(name) {
    const result = [];
    for (const child of this.children) {
      if (name === '*' || child.tagName === name || child.localName === name) result.push(child);
      result.push(...child.getElementsByTagName(name));
    }
    return result;
  }

  getElementsByTagNameNS(namespaceURI, localName) {
    const result = [];
    for (const child of this.children) {
      const namespaceMatches = namespaceURI === '*' || child.namespaceURI === namespaceURI;
      if (namespaceMatches && child.localName === localName) result.push(child);
      result.push(...child.getElementsByTagNameNS(namespaceURI, localName));
    }
    return result;
  }
}

class XmlDocument {
  constructor(rootElement = null) {
    this.documentElement = rootElement;
  }

  querySelector(selector) {
    return selector === 'parsererror' ? null : null;
  }

  createElementNS(namespaceURI, tagName) {
    return new XmlElement(namespaceURI, tagName);
  }

  getElementsByTagName(name) {
    if (!this.documentElement) return [];
    const own = name === '*' || this.documentElement.tagName === name || this.documentElement.localName === name
      ? [this.documentElement]
      : [];
    return [...own, ...this.documentElement.getElementsByTagName(name)];
  }

  getElementsByTagNameNS(namespaceURI, localName) {
    if (!this.documentElement) return [];
    const ownNamespaceMatches = namespaceURI === '*' || this.documentElement.namespaceURI === namespaceURI;
    const own = ownNamespaceMatches && this.documentElement.localName === localName ? [this.documentElement] : [];
    return [...own, ...this.documentElement.getElementsByTagNameNS(namespaceURI, localName)];
  }
}

class FakeDOMParser {
  parseFromString(xml) {
    const tokens = String(xml)
      .replace(/<\?xml[\s\S]*?\?>/gi, '')
      .replace(/<!--[\s\S]*?-->/g, '')
      .match(/<[^>]+>|[^<]+/g) || [];
    const stack = [];
    let rootElement = null;

    for (const token of tokens) {
      if (!token.trim()) continue;
      if (token.startsWith('</')) {
        stack.pop();
        continue;
      }
      if (token.startsWith('<!')) continue;
      if (!token.startsWith('<')) {
        if (stack.length) stack.at(-1)._text += decodeXml(token);
        continue;
      }

      const selfClosing = /\/\s*>$/.test(token);
      const match = token.match(/^<\s*([^\s/>]+)([\s\S]*?)\/?\s*>$/);
      if (!match) return new XmlDocument(new XmlElement('', 'parsererror'));
      const [, tagName, attributeText] = match;
      const namespaceURI = tagName.startsWith('wegwichtel:') ? POI_NAMESPACE : GPX_NAMESPACE;
      const element = new XmlElement(namespaceURI, tagName);
      const attributePattern = /([^\s=]+)\s*=\s*(["'])(.*?)\2/g;
      for (const attribute of attributeText.matchAll(attributePattern)) {
        element.setAttribute(attribute[1], decodeXml(attribute[3]));
      }

      if (stack.length) stack.at(-1).appendChild(element);
      else if (!rootElement) rootElement = element;
      else return new XmlDocument(new XmlElement('', 'parsererror'));
      if (!selfClosing) stack.push(element);
    }

    if (!rootElement || stack.length) return new XmlDocument(new XmlElement('', 'parsererror'));
    return new XmlDocument(rootElement);
  }
}

function serializeElement(element) {
  const attributes = [...element.attributes]
    .map(([name, value]) => ` ${name}="${escapeXml(value)}"`)
    .join('');
  const content = escapeXml(element._text) + element.children.map(serializeElement).join('');
  return `<${element.tagName}${attributes}>${content}</${element.tagName}>`;
}

class FakeXMLSerializer {
  serializeToString(document) {
    return serializeElement(document.documentElement);
  }
}

class FakeStorage {
  constructor() {
    this.values = new Map();
    this.failNext = false;
  }

  getItem(key) {
    return this.values.has(key) ? this.values.get(key) : null;
  }

  setItem(key, value) {
    if (this.failNext) {
      this.failNext = false;
      const error = new Error('quota');
      error.name = 'QuotaExceededError';
      throw error;
    }
    this.values.set(String(key), String(value));
  }

  removeItem(key) {
    this.values.delete(String(key));
  }
}

class FakeCustomEvent extends Event {
  constructor(type, options = {}) {
    super(type);
    this.detail = options.detail;
  }
}

class FakeFileReader extends EventTarget {
  readAsText(file) {
    queueMicrotask(() => {
      this.result = file.content || '';
      this.dispatchEvent(new Event('load'));
    });
  }

  readAsDataURL(file) {
    queueMicrotask(() => {
      const type = file.type || 'application/octet-stream';
      this.result = `data:${type};base64,VEVTVA==`;
      this.dispatchEvent(new Event('load'));
    });
  }
}

async function loadLocalRoutes() {
  const sourcePath = path.join(root, 'public/js/local-routes.js');
  const source = await fs.readFile(sourcePath, 'utf8');
  const localStorage = new FakeStorage();
  const document = new EventTarget();
  const events = [];
  document.addEventListener('wegwichtel:local-routes-changed', event => events.push(event.detail));

  const context = {
    CustomEvent: FakeCustomEvent,
    DOMParser: FakeDOMParser,
    Event,
    EventTarget,
    FileReader: FakeFileReader,
    XMLSerializer: FakeXMLSerializer,
    crypto: { randomUUID: () => '11111111-2222-4333-8444-555555555555' },
    document,
    globalThis: null,
    localStorage,
    queueMicrotask,
    Wegwichtel: {}
  };
  context.globalThis = context;
  vm.runInNewContext(source, context, { filename: sourcePath });
  return { api: context.Wegwichtel.LocalRoutes, events, localStorage };
}

const sampleGpx = `<?xml version="1.0" encoding="UTF-8"?>
<gpx version="1.1" creator="Test" xmlns="${GPX_NAMESPACE}" xmlns:wegwichtel="${POI_NAMESPACE}">
  <metadata><name>Alter Name</name></metadata>
  <wpt lat="50.1000" lon="10.1000"><name>Import</name><extensions><wegwichtel:poiId>77</wegwichtel:poiId></extensions></wpt>
  <trk><name>Weg</name><trkseg>
    <trkpt lat="50.1000" lon="10.1000"><ele>100</ele></trkpt>
    <trkpt lat="50.1010" lon="10.1020"><ele>112</ele></trkpt>
  </trkseg></trk>
</gpx>`;

test('local route package stores GPX and JSON separately and reconstructs an app route', async () => {
  const { api, events, localStorage } = await loadLocalRoutes();
  const routeId = api.createRouteId();
  assert.equal(routeId, 'local-11111111-2222-4333-8444-555555555555');

  const saved = api.save({
    id: routeId,
    gpx: sampleGpx,
    route: { id: routeId, name: 'Neue Route', description: 'Lokal gespeichert' },
    pois: [
      {
        id: 101,
        title: 'Start',
        description: 'Erster POI',
        lat: 50.1,
        lon: 10.1,
        triggerRadiusM: 30,
        audio: { dataUrl: 'data:audio/mpeg;base64,QQ==', name: 'start.mp3' },
        images: [{ id: 'img-1', dataUrl: 'data:image/jpeg;base64,Qg==', caption: 'Bild' }]
      },
      {
        id: 102,
        title: 'Ziel',
        description: 'Zweiter POI',
        lat: 50.101,
        lon: 10.102,
        triggerRadiusM: 25,
        images: []
      }
    ]
  });

  assert.equal(saved.route.name, 'Neue Route');
  assert.equal(saved.pois.length, 2);
  assert.equal(events.at(-1).action, 'saved');
  assert.equal(events.at(-1).id, routeId);

  const prefix = api.STORAGE_PREFIX;
  const encodedId = encodeURIComponent(routeId);
  const gpx = localStorage.getItem(`${prefix}.${encodedId}.gpx`);
  const metadata = JSON.parse(localStorage.getItem(`${prefix}.${encodedId}.json`));

  assert.match(gpx, /<wpt lat="50\.1" lon="10\.1">/);
  assert.match(gpx, /<wegwichtel:poiId>101<\/wegwichtel:poiId>/);
  assert.ok(gpx.indexOf('<wpt') < gpx.indexOf('<trk>'), 'GPX waypoints must be serialized before the track');
  assert.equal(metadata.route.name, 'Neue Route');
  assert.equal(metadata.pois[0].audio.name, 'start.mp3');
  assert.equal('gpx' in metadata, false);
  assert.equal('_source' in metadata.route, false);

  const appRoute = api.getAppRoute(routeId);
  assert.equal(appRoute.source, 'local');
  assert.equal(appRoute.local, true);
  assert.equal(appRoute.pois.length, 2);
  assert.equal(appRoute.pois[0].audioUrl, 'data:audio/mpeg;base64,QQ==');
  assert.equal(appRoute.pois[0].images[0].url, 'data:image/jpeg;base64,Qg==');
  assert.equal(appRoute.points.length, 2);
  assert.ok(appRoute.distanceM > 0);
  assert.equal(Math.round(appRoute.elevationGainM), 12);
  const listed = api.listAppRoutes();
  assert.equal(listed.length, 1);
  assert.equal(listed[0].id, routeId);
});

test('GPX waypoint import reads stable POI ids and validates coordinates', async () => {
  const { api } = await loadLocalRoutes();
  const imported = api.parseWaypoints(sampleGpx);

  assert.equal(imported.length, 1);
  assert.equal(imported[0].id, 77);
  assert.equal(imported[0].title, 'Import');
  assert.equal(imported[0].lat, 50.1);
  assert.equal(imported[0].lon, 10.1);

  assert.match(api.emptyGpx('A & B'), /<name>A &amp; B<\/name>/);
  assert.throws(() => api.parseWaypoints('<not-gpx></not-gpx>'), /GPX-Datei ist nicht gültig/);
  assert.throws(() => api.syncGpx(sampleGpx, { name: 'Fehler' }, [{ id: 1, title: 'Ohne Position' }]), /gültige Koordinaten/);
});

test('remove updates index and dispatches a local-route change event', async () => {
  const { api, events } = await loadLocalRoutes();
  api.save({
    id: 'local-remove',
    gpx: sampleGpx,
    route: { name: 'Entfernen' },
    pois: []
  });

  assert.equal(api.list().length, 1);
  api.remove('local-remove');
  assert.equal(api.list().length, 0);
  assert.equal(events.at(-1).action, 'removed');
  assert.equal(events.at(-1).id, 'local-remove');
  assert.throws(() => api.getAppRoute('local-remove'), /nicht gefunden/);
});

test('quota failure rolls back package writes and keeps the previous package readable', async () => {
  const { api, localStorage } = await loadLocalRoutes();
  api.save({
    id: 'local-quota',
    gpx: sampleGpx,
    route: { name: 'Vorher' },
    pois: []
  });

  localStorage.failNext = true;
  assert.throws(() => api.save({
    id: 'local-quota',
    gpx: sampleGpx,
    route: { name: 'Nachher' },
    pois: []
  }), /Browser-Speicher ist voll/);

  assert.equal(api.get('local-quota').route.name, 'Vorher');
});

test('file helpers support native text and FileReader-backed media data URLs', async () => {
  const { api } = await loadLocalRoutes();

  assert.equal(await api.readFileAsText({ text: async () => '<gpx></gpx>' }), '<gpx></gpx>');
  assert.equal(await api.readFileAsText(null), '');

  const media = await api.fileToDataUrl({ name: 'ton.mp3', size: 4, type: 'audio/mpeg' });
  assert.equal(media.name, 'ton.mp3');
  assert.equal(media.size, 4);
  assert.equal(media.type, 'audio/mpeg');
  assert.match(media.dataUrl, /^data:audio\/mpeg;base64,/);
  assert.equal(await api.fileToDataUrl(null), null);
});